Antibiotics / Cell Culture / Fungii infection

Dr. Schuppenhauer:
If you are using cell culture grade antibiotic solutions from GIBCO,
then it is not reasonable to think that the antibiotic solutions
contain fungal spores. If you are using non-cell culture grade
materials, at the very least the solutions should be sterile filtered
before use.
Rather than "fight the fungi with antimycotica," which are notoriously
ineffective, I suggest you review your aseptic procedures. The best
approach is to make sure the infection does not occur in the first
place. In this regard, I would recommend AGAINST the use of any
antibiotics. Antibiotics can actually mask or cover up true
procedural flaws. If you have antibiotics in your medium and you
"test for bacterial infection" soon after making up the medium, you
will get a negative test result even if you have infections, because
of the presence of the antibiotic. One of your respondents noted that
the antibiotics can affect mammalian cell growth, and this is true.
Yet another reason to avoid them!
Note also: once you have fungal infection in your system, it may be
difficult to eradicate it from the system itself. Some fungal spores
are resistant to normal autoclaving procedures. Thus, even if your
culture medium is "clean," your cultures could be re-infected from the
hardware. This is especially problemmatic with reactors where you
cannot see inside (i.e., not made of glass), or where you have tubings
and connectors. I would recommend a chemical sterilant such as ALCIDE
to thoroughly clean the reactor, and as I said earlier, a thorough
review of your procedures to determine at what points along the line
aseptic techniques may be compromised.
______________________________ Reply Separator _________________________________
Subject: Antibiotics / Cell Culture / Fungii infection
Author: michaelrs at ezzeus.vmsmail.ethz.ch at NOTE
Date: 4/23/94 6:42 PM
---------------------- Original Header Lines (From NOTE) -----------------------
Nntp-Posting-Host: bourne33.ethz.ch
------------------------------- Message Contents -------------------------------
We have comme across several cultivations of mammalian cells being "inf
cted"
by fibric material. The media we are using is made up from pulver and then
sterile filtered, tested for (bacterial) infection. When running continous
processes after 2/3 weeks or so we encounter clogging due to some fibres that
attached to our reactor inside. Of course we did sterile testing before. To
insure we can do the experiments we want to do we add antibiotics,
penicillin/streptomycin/neomycin. All material is from GIBCO or Sigma, approved
quality.
Is it reasonble to believe that the fungii we saw under the
microscopes/scanning microscopes are imported through the antibiotics ?
As antibiotics are produced from fungii, could it be that during
downstreamprocessing the spores are not totally removed, and end up in the
suspensions ?
Does anyone have had similiar experience/thoughts ?
Should I fight the fungii with antimycotica ?
Michael R Schuppenhauer
ETH Zurich, Switzerland
Dept. of Chem Eng
michaelrs at ezzeus.vmsmail.ethz.ch